Mulching is particularly beneficial for both newly planted and established hedges…
Mulch is simply “a layer of material applied to the surface of an area of soil.” to:
• Minimise weed growth
• Help retain moisture, especially in summer
• Improve the soil’s texture, fertility and general health
• Discourage pests
• Encourage helpful organisms
• Neaten and improve the garden’s appearance
• Shield roots from extreme temperatures
• Prevent food crops from touching the soil
• Help create a wildlife habitat
The definition of ‘mulch’ encompasses artificial barriers such as water-proof plastic sheeting or woven permeable fabrics and while they achieve a few of the functions (especially suppressing weeds) they do little or nothing to improve the soil itself. Other non-biodegradable (and non-fertilising) mulches include natural materials like gravel, chippings, pebbles, shingle slate and seashells. Industrial products are also recycled into mulch though crushed CDs or tumbled glass are best used in containers rather than as ground cover.
Biodegradable mulches, though, may not be quite so effective at keeping weeds down (they still do a pretty good job) or be so long-lasting but they will improve soil structure and add nutrients as they rot down,. Compost (garden or spent mushroom), leaf mould, well-rotted manure, wood or bark chippings or even seaweed all make excellent mulches for use not only under hedges but across the garden. In forthcoming posts, we’ll look at some of these in more detail.
WHEN TO APPLY
Mulches work best when the soil is warm and moist – and that means applying them from mid to late spring and in autumn. Mulching at other times is not necessarily a waste of time as it will improve under-hedge habitats for wildlife and offer useful added protection for newly plantings.
• Biodegradable mulches should be applied with a depth of at least 5cm – 7.5cm+ is better
• Remove weeds and their roots and ensure the soil is moist before applying
• For hedging plants (whether planted as specimens or a hedge) extend the mulch to at least the radius of their canopy…
• …but do not let the mulch abut the stems or trunk
• Do not just use uncomposted garden waste as a mulch – this could introduce pests, weeds, and/or diseases to the area
• A mulched area will need extra water to ensure it reaches the roots
• Fertiliser can be applied directly onto mulch
• Let one application rot down before applying another to avoid creating a hard layer of material which can prevent water from seeping down
• White fungal mycelium of saprophytic fungi may appear on the mulch – these are almost always harmless and no action is required